Blockchain 101 Certification Blockchain 101 Certification Consensus Mechanisms & Protocols 1 — Questions and Answers
Question 1: Which consensus mechanism requires participants to solve computationally intensive puzzles to validate transactions?
- Proof of Stake
- Proof of Work (Correct answer)
- Delegated Proof of Stake
- Proof of Authority
Correct answer: Proof of Work
Proof of Work (PoW) requires miners to expend computational energy solving cryptographic puzzles to add blocks to the chain.
Question 2: In a Proof of Stake consensus model, what determines a validator's chance of being selected to create the next block?
- Hash rate
- Network latency
- Amount of staked cryptocurrency (Correct answer)
- Number of transactions processed
Correct answer: Amount of staked cryptocurrency
In PoS, validators are chosen to propose new blocks proportionally based on the amount of cryptocurrency they have staked as collateral.
Question 3: What is a Byzantine Fault in the context of distributed blockchain consensus?
- A network timeout error
- Arbitrary or malicious behavior by a node (Correct answer)
- A double-spend transaction
- A fork in the blockchain
Correct answer: Arbitrary or malicious behavior by a node
A Byzantine Fault refers to a node behaving arbitrarily or maliciously, sending conflicting information to different parts of the network.
Question 4: Which consensus protocol is commonly used in permissioned enterprise blockchains like Hyperledger Fabric?
- Proof of Work
- Nakamoto Consensus
- Practical Byzantine Fault Tolerance (PBFT) (Correct answer)
- Proof of Burn
Correct answer: Practical Byzantine Fault Tolerance (PBFT)
PBFT is widely used in permissioned blockchains because it achieves consensus among known, trusted nodes without energy-intensive mining.
Question 5: What is a blockchain fork?
- A cryptographic key split
- A divergence in the blockchain creating two separate chains (Correct answer)
- A type of smart contract
- A network upgrade tool
Correct answer: A divergence in the blockchain creating two separate chains
A fork occurs when the blockchain diverges into two paths, either temporarily (soft fork) or permanently (hard fork), due to rule changes or disagreements.
Question 6: In Delegated Proof of Stake (DPoS), who actually validates transactions?
- All token holders simultaneously
- A small number of elected delegates (Correct answer)
- Anonymous miners
- Only the blockchain founder
Correct answer: A small number of elected delegates
In DPoS, token holders vote to elect a limited set of delegates who are responsible for validating transactions and producing blocks.
Blockchain 101 Certification Blockchain 101 Certification Consensus Mechanisms & Protocols 1
Which consensus mechanism requires participants to solve computationally intensive puzzles to validate transactions?